In recent years, optical modules (e.g., IR sensors using light in the infrared (IR) region) and electronic devices having the same have been widely used. IR sensors may irradiate light in the infrared wavelength range and may receive the light reflected from an object to sense the proximity of the object, measure ambient illuminance, or determine the shape of the object. These IR sensors may include, for example, proximity sensors, illuminance sensors, or iris sensors.
IR sensors may use light in the near-infrared (NIR) region (e.g., 810 to 850 nm) to improve iris recognition performance without being affected by ambient light sources. However, the wavelength range of light emitted by IR LEDs corresponding to light-emitting units of the IR sensors may include a region (e.g., 700 to 780 nm) in the visible wavelength range, and thus visible light emitted by the IR LEDs may be exposed to the outside.
Conventional IR sensors may have reflective coating or absorbent coating applied to lenses thereof to prevent and/or reduce visible light from being exposed to the outside. However, due to a wavelength shift depending on the incidence angle of light, the reflective coating may not completely prevent visible light from being exposed to the outside. Further, the absorbent coating may be less effective due to degradation in the transmittance of infrared radiation and a decrease in the visible-light blocking rate.